Lightstreamer .Net Adapter 1.7
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IMetadataProvider.GetSchema Method

Called by Lightstreamer Kernel through the Remote Server to resolve a Schema name supplied in a Request. The names of the Fields in the Schema must be returned. 

Possibly, the content of a Schema may be dependant on the User who is issuing the Request, on the specific Session instance or on the Group to which the Request is related. 

A special case is when the Schema name is made of a space-separated list of the names of the fields in the Schema. This convention is used by some of the subscription methods provided by the various client libraries. The specifications for these methods require that "A LiteralBasedProvider or equivalent Metadata Adapter is needed on the Server in order to understand the Request". When any of these interface methods is used by client code accessing this Metadata Adapter, the supplied schema argument should be inspected as a space-separated list of field names and an array with these names in the same order should be returned; returning decorated or alternative field names is also possible: they will be associated to the corresponding names used in the supplied schema by client library code. 

This method runs in the Server thread pool specific for the Data Adapter that supplies the involved items, if defined. 

 

C++
string[] GetSchema(string user, string sessionID, string id, string schema);
C#
string[] GetSchema(string user, string sessionID, string id, string schema);
Visual Basic
Function GetSchema(user As string, sessionID As string, id As string, schema As string) As string()
Parameters 
Description 
string user 
A User name. 
string sessionID 
The ID of a Session owned by the User. 
string id 
The name of a Group whose Items the Schema is to be applied to. 
string schema 
A Schema name. 

An array with the names of the Fields in the Schema.

Exceptions 
Description 
in case the supplied Group name is not recognized.  
in case the supplied Schema name is not recognized.